Devices of this type are well known in the prior art, as illustrated, for example, in patent documents U.S. Pat. No. 3,470,697, FR-2,532,084 and FR-2,658,466.
Recent research has shown that a good many drivers, when confronted with an emergency braking situation, underestimate the risks actually involved and, having braked sharply, release their braking effort under circumstances in which, on the contrary, it is absolutely essential that they maintain a substantial braking effort in order to avoid the accident.
This observation has led to the development of various solutions in an attempt to alleviate any possible shortcomings in the behaviour of an inexperienced or panic-stricken driver.